<!doctype html>
<html>

<head>
  <title>Line Chart</title>
  <script src="../dist/Chart.bundle.js"></script>
  <script src="http://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
  <style>
    canvas {
        -moz-user-select: none;
        -webkit-user-select: none;
        -ms-user-select: none;
    }
  </style>
</head>

<body>
  <div style="width:75%;">
    <canvas id="canvas"></canvas>
  </div>
  <br>
  <br>
  <button id="randomizeData">Randomize Data</button>
  <button id="addDataset">Add Dataset</button>
  <button id="removeDataset">Remove Dataset</button>
  <button id="addData">Add Data</button>
  <button id="removeData">Remove Data</button>
  <script>
    var MONTHS = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];

    var randomScalingFactor = function() {
      return Math.round(Math.random() * 100 * (Math.random() > 0.5 ? -1 : 1));
    };
    var randomColorFactor = function() {
      return Math.round(Math.random() * 255);
    };
    var randomColor = function(opacity) {
      return 'rgba(' + randomColorFactor() + ',' + randomColorFactor() + ',' + randomColorFactor() + ',' + (opacity || '1') + ')';
    };

    var config = {
      type: 'line',
      data: {
        labels: ["January", "February", "March", "April", "May", "June", "July"],
        datasets: [{
          label: "My First dataset",
          data: [randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor()],
        }, {
          label: "My Second dataset",
          data: [randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor()],
        }, {
          label: "My Third dataset",
          data: [randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor()],
        }, {
          label: "My Third dataset",
          data: [randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor(), randomScalingFactor()],
        }]
      },
      options: {
        responsive: true,
        title:{
          display:true,
          text:"Chart.js Line Chart - Stacked Area"
        },
        tooltips: {
          mode: 'label',
        },
        hover: {
          mode: 'label'
        },
        scales: {
          xAxes: [{
            scaleLabel: {
              display: true,
              labelString: 'Month'
            }
          }],
          yAxes: [{
            stacked: true,
            scaleLabel: {
              display: true,
              labelString: 'Value'
            }
          }]
        }
      }
    };

    $.each(config.data.datasets, function(i, dataset) {
      var color = randomColor(1);
      dataset.borderColor = color;
      dataset.backgroundColor = color;
      dataset.pointBorderColor = color;
      dataset.pointBackgroundColor = color;
      dataset.pointBorderWidth = 1;
    });

    window.onload = function() {
      var ctx = document.getElementById("canvas").getContext("2d");
      window.myLine = new Chart(ctx, config);
    };

    $('#randomizeData').click(function() {
      $.each(config.data.datasets, function(i, dataset) {
        dataset.data = dataset.data.map(function() {
          return randomScalingFactor();
        });

      });

      window.myLine.update();
    });

    $('#addDataset').click(function() {
      var newDataset = {
        label: 'Dataset ' + config.data.datasets.length,
        borderColor: randomColor(0.4),
        backgroundColor: randomColor(0.5),
        pointBorderColor: randomColor(0.7),
        pointBackgroundColor: randomColor(0.5),
        pointBorderWidth: 1,
        data: [],
      };

      for (var index = 0; index < config.data.labels.length; ++index) {
        newDataset.data.push(randomScalingFactor());
      }

      config.data.datasets.push(newDataset);
      window.myLine.update();
    });

    $('#addData').click(function() {
      if (config.data.datasets.length > 0) {
        var month = MONTHS[config.data.labels.length % MONTHS.length];
        config.data.labels.push(month);

        $.each(config.data.datasets, function(i, dataset) {
          dataset.data.push(randomScalingFactor());
        });

        window.myLine.update();
      }
    });

    $('#removeDataset').click(function() {
      config.data.datasets.splice(0, 1);
      window.myLine.update();
    });

    $('#removeData').click(function() {
      config.data.labels.splice(-1, 1); // remove the label first

      config.data.datasets.forEach(function(dataset, datasetIndex) {
        dataset.data.pop();
      });

      window.myLine.update();
    });
  </script>
</body>

</html>
